This section provides background information related to the present disclosure which is not necessarily prior art.
A projector with an ultra-short focus, with a low projection ratio, and at a short distance from a screen, can project a large picture, but may come with some difficulties with debugging and installation in that if the projector is slightly shift, then the picture may be seriously deformed and displaced, thus making it difficult to align the image projected by the projector with the screen, which may seriously degrade the effect of operating the projector.
In the prior art, the projection device is typically debugged manually very often to determine the optimum projection position, but the projection device may be debugged so difficultly and troublesomely that it may be debugged inefficiently.
In summary, if the projection device is debugged frequently as in the prior art to calibrate the effect of projecting the projected picture onto the screen, then the projection device may be debugged so difficultly and troublesomely that it may be debugged inefficiently.